Axial compressor

About: Axial compressor is a research topic. Over the lifetime, 12035 publications have been published within this topic receiving 127766 citations.

Fixed blading of axial compressors

Abstract: Fixed blading for an axial compressor constituted by a succession of blades fixed on at least one annular wall and a method of operating the same. Fluid passing through a passage between adjacent blades is drawn into a suction opening and the pressure at the suction opening is maintained substantially equal to the flow static pressure in the passage.

Performance of an Axial Flow Turbine Driven by Multiple Pulse Detonation Combustors

Abstract: Experimental studies were carried out to investigate the performance of a hybrid propulsion system integrating an axial flow turbine with multiple pulse detonation combustors. The integrated system consisted of a circular array of six pulse detonation combustor (PDC) tubes exhausting through an axial flow turbine. Turbine component performance was quantified by measuring the amount of power generated by the turbine section. Direct comparisons of specific power output and turbine efficiency between a PDC driven turbine and a turbine driven by a traditional steady flow combustor were made. It was found that the PDC driven turbine had comparable performance to that of a steady burner driven turbine across the operating map of the turbine.

Analysis of rotating stall onset in high speed axial flow compressors

Abstract: Ahstrart A computational and theoretical procedure is described for the analysis of flow instability in high speed, muhistage COInpreSWTS. Specifically, lhe paper presenu the first rigorous analysis of the type of twedirnensianal, long wavelength, small amplitude, compressible flow perturbations which have been experimentally observed to develop into rotating stall. The analysis shows that compressibility has a stabilizing influence for both singlestage and multistage machines. A much more impwtant conclusion, however, is that the axial structure of the perturbations, as well as the behavior of the least stable eigenmode (which determines stability for the machine), is similar for the high speed situation and for incompressible flow. The rotating stall onset behaviors of high speed and low speed machines are therefore predicted to be similar in many respecrs. One key feature of this similarity is &at it is the overall slope of the (futl) compressor pressure rise characteristic, rather than the slope of any single stage, that determines instability onset. Numerical resulb are given to illusbate these points, as well as to show the specific influence of parameters such as blade tip Mach number and compessot length.

Control means for a gas turbine engine

Abstract: Clearance control means is provided for a gas turbine engine In one embodiment relating to compressor blade clearance, means is provided for developing a first signal representative of the actual compressor casing temperature, a second signal representative of compressor inlet gas temperature, and a third signal representative of compressor speed Schedule means is provided for receiving the gas temperature and compressor speed signals and developing a schedule output signal The schedule output signal is representative of a reference casing temperature at which a predetermined compressor blade stabilized clearance is provided Means is provided for comparing the actual compressor casing temperature signal and the reference casing temperature signal and developing a clearance control signal representative of the difference therebetween The clearance control signal is coupled to a control valve which controls a flow of air to the compressor casing to control the clearance between the compressor blades and the compressor casing Means is provided for modification of the clearance control signal to accommodate transient characteristics Other embodiments are disclosed

Design and transient computational fluid dynamics study of a continuous axial flow ventricular assist device.

Abstract: A ventricular assist device (VAD), which is a miniaturized axial flow pump from the point of view of mechanism, has been designed and studied in this report. It consists of an inducer, an impeller, and a diffuser. The main design objective of this VAD is to produce an axial pump with a streamlined, idealized, and nonobstructing blood flow path. The magnetic bearings are adapted so that the impeller is completely magnetically levitated. The VAD operates under transient conditions because of the spinning movement of the impeller and the pulsatile inlet flow rate. The design method, procedure, and iterations are presented. The VAD's performance under transient conditions is investigated by means of computational fluid dynamics (CFD). Two reference frames, rotational and stationary, are implemented in the CFD simulations. The inlet and outlet surfaces of the impeller, which are connected to the inducer and diffuser respectively, are allowed to rotate and slide during the calculation to simulate the realistic spinning motion of the impeller. The flow head curves are determined, and the variation of pressure distribution during a cardiac cycle (including systole and diastole) is given. The axial oscillation of impeller is also estimated for the magnetic bearing design. The transient CFD simulation, which requires more computer resources and calculation efforts than the steady simulation, provides a range rather than only a point for the VAD's performance. Because of pulsatile flow phenomena and virtual spinning movement of the impeller, the transient simulation, which is realistically correlated with the in vivo implant scenarios of a VAD, is essential to ensure an effective and reliable VAD design.